In the field of semiconductor technology, a RF front-end module (RF FEM) is a key component in many wireless communication devices such as mobile phones, tablet PCs, and the like. A RF switch is typically an important component of a RF front-end module. A RF switch is required to have high signal fidelity, low insertion loss, good linearity, good switch isolation, and small signal distortion.
In the prior art, RF switches are made of gallium arsenide (GaAs) transistors, which involves expensive manufacturing and packaging parts. In recent years, with advance in semiconductor technology, RF switches can be implemented using metal oxide semiconductor field effect transistors on a silicon-on-insulator substrate (SOI MOS), and the SOI MOS RF switches can have performance levels similar to those of GaAs switches.
However, the SOI silicon thin film MOSFET transistors and metal interconnect wires may couple strongly to the buried oxide layer. If an effective RF insulation measure is not taken, then the linearity and harmonic distortion of the RF switches may be affected.
Thus, there is a need for novel techniques to solve the problems of the prior art.